Microwave Journal

Buck Converter: LTC3637

March 24, 2014

3637Linear Technology announces the LTC3637, a 76 V input-capable high efficiency buck converter that delivers up to 1 A of continuous output current. It operates from an input voltage range of 4 to 76 V, making it ideal for telecom, industrial, avionic and automotive applications.

The LTC3637 utilizes a programmable peak current-mode design to optimize efficiency over a broad range of output currents. It delivers efficiencies as high as 90% and requires only 12 µA of quiescent current, maximizing battery run time. A user-programmable output current limit can set output current from 100mA to 1A as required by the application. The LTC3637 can be programmed with fixed output voltages of 1.8V, 3.3V or 5V or a resistor divider can be used to program outputs from VIN to 0.8V. The LTC3637’s thermally enhanced MSOP or 3mm x 5mm DFN packages offer additional pin spacing required for high voltage inputs. The combination of its MSOP or DFN package and only four tiny externals provide a highly compact solution footprint for a wide array of applications.

The LTC3637 utilizes an internal 350 mΩ power MOSFET that draws only 12µA at no load while maintaining output voltage regulation, making it ideal for always-on battery-powered applications. Due to the inherent stability of the converter, no external compensation is required, thereby simplifying design and minimizing the solution footprint. Additional features include a precise 0.8V ±1% feedback voltage reference and internal or external soft-start.

Pricing for the 16-Lead TSSOP version, the LTC3637EMSE and the DFN version, the LTC3637EDHC, starts at $3.20 each. Industrial temperature versions, the LTC3637IMSE and LTC3637IDHC, are tested and guaranteed to operate from a -40°C to 125°C operating junction temperature, priced starting at $3.52 each. Automotive temperature versions, the LTC3637HMSE and LTC3637HDHC, are tested and guaranteed to operate from a -40°C to 150°C operating junction temperature, priced starting at $3.77 each.

Finally high reliability versions, the LTC3637MPMSE and LTC3637MPDHC, are tested and guaranteed to operate from a -55°C to 150°C operating junction temperature, priced starting at $9.50 each. All pricing is in 1,000-piece quantities and all versions are available from stock. For more information, visit www.linear.com/product/LTC3637.

Summary of Features: LTC3637

  • Wide Operating Input Voltage Range:
  • 4V to 76V
  • Internal 350mΩ Power MOSFET
  • No Compensation Required
  • Adjustable 100mA to 1A Maximum Output Current
  • Low Dropout Operation:
  • 100% Duty Cycle
  • Low Quiescent Current: 12µA
  • Wide Output Range:
  • 0.8V to VIN
  • 0.8V ±1% Feedback Voltage Reference
  • Precise RUN Pin Threshold
  • Internal & External Soft-Start
  • Programmable 1.8V, 3.3V, 5V or Adjustable Output
  • Few External Components Required
  • Programmable Input Overvoltage Lockout
  • Low Profile (0.75mm) 3mm x 5mm DFN & Thermally Enhanced MSE16 Packages